Its located under the distributor cap and the rotor http://www.napaonline.com/Search/MultiImagePopup.aspx?A=MPEEP310SB_0159421868&An=599001+599999+101990+109999+50090+59999+2090037+3999999+13178 should just pop off after the cap is removed But if you have to ask were it's located you might be better off having someone with mechanical experience help you http://repairpal.com/directory?address=37349&car_brand_names=Nissan